Based on virus-like particle (VLP) technology the VRC has developed a candidate Chikungunya virus (ChikV) vaccine that induced potentially protective levels of neutralizing antibodies in healthy volunteers in a Phase I clinical trial. A small lot of vaccine has already been manufactured with existing funding, sufficient for conduct of a limited Phase 1b/II clinical trial in an endemic region of the Americas. This task is to advance this vaccine in collaboration with government/non-governmental partners, to manufacture an additional CHIK VLP lot(s) to support an expanded vaccine efficacy trial in the setting of the ongoing ChikV outbreak occurring in the Americas.